It will take more than rising racial diversity to win elections. The party shouldn't take any group for granted.
First, thanks, Ruy Teixeira, for your long history of thinking about these questions. Second, and at the risk of harping, I'd like to point out that lots of scholars outside the discipline of politics aren't just failing to take this information into account. Rather, believing that "demographics = (progressive} destiny" and that members of disfavored groups share the values of radical white scholars (or, rather, vice versa) is a sign of motivated reasoning. Considering religious beliefs and other factors would undermine these convictions. Not incidentally, it would also call the identifications--therefore identity--of radical white scholars into question. We all tend to resist the destabilizing of our most cherished identities. But the "brand" of radical intellectuals in bound up with their pedagogy about the radical, virtuous essence of BIPOC, AAPIDA, and queer "folx." Any data that complicate this reading of alterity (yeah, jargon) are anathema.
There is a fifth lesson: Religious votes change with immigration. Many if not all Hispanic Immigrants are Catholic and Catholics do tend to vote Republican at this point. The Catholic Church is still pretty clear about gender, euthanasia and abortion. Hispanics are still, I believe, the largest group of immigrants too. Trump was an atheistic anomaly for a Republican; so he did not rally Catholic voters the way most post Reagan Republicans have. I suspect he would have won if he had catered a bit more the the Catholic Hispanic voter. Still he shockingly pulled in tremendous numbers of Hispanic votes despite his rather Draconian immigration policies. Bush understood the immigrant Catholic vote and catered to the Hispanic voter. He was willing to say he looked to God for guidance, enlightenment and purification. He admitted he was a humble recovering sinner, Catholics like that. I like that. That got him two terms.
It looks like the important demographic change is the increase in college educated voters as a proportion of the total.
I always thought, as others have since remarked, that the big problem with the author's analysis was that they falsely assumed the definition of "white" was stable enough to allow them to confidently project a decline in the "white" population.